The present invention is relates generally to a method and system for rapid press forming and consolidation of a sheet of thermoformable material, and more particularly relates to a method and system for rapid press forming and consolidation of a sheet of thermoformable material for molding articles with complex shapes in a manner that applies pressure uniformly in all directions, to substantially eliminate wrinkles in the formed product.
A significant problem in press forming of articles with complex shapes is the formation of wrinkles in the formed product, resulting in considerable waste due to the production of malformed articles, and the need for additional time consuming and laborious steps for final finishing and polishing of the press formed articles to achieve an acceptable final product. One known method of hydroforming of composite materials to shape complex structures to limit wrinkling or rupture of the composite during the shaping process involves providing a press having a fluid chamber defining a cavity for providing pressurized fluid to a surface of a blank, with a blank support for holding the blank having an opening defining a cavity, so that a punch can move through the opening into the fluid chamber.
Another known method provides for fluid forming of oriented thermoplastics from elongated tubular blanks, and involves providing a longitudinally oriented tubular blank formed in a cavity to conform the tubular blank to a predetermined shape of the fluid forming cavity.
Another known technique involves using a punch made of massive rubber, and an apparatus is also known for deforming a sheet of thermoplastic material by sequentially pressing cold tips of projections from a series of moveable combs against first and second faces of a hot sheet of the material.
However, it has been found that none of the foregoing conventional methods of molding articles has been found to be completely satisfactory in eliminating wrinkles in articles formed to have complex shapes. A need therefore remains for a method and system for rapid press forming and consolidation of a sheet of thermoformable material, with an indexed suspension and the film suspension technique, and a hydraulic punch that applies pressure uniformly in all directions, to substantially eliminate wrinkles in the formed product. The present invention meets this and other needs.